Investigation of Meta-Anthracite in Newport and Providence Counties, Rhode Island: Petrography, Chemical Characteristics, and Geology of Deposits: I. Investigation of the Field and the Physical and Chemical Characteristics of the Deposits; II. Preliminary Geologic Study of the Portsmouth and Cranston Areas, Rhode Island; III. General Conclusions Page: 22

                                
R.I. 4276 "

Ge6logic Relations
Only one meta-anthracite bed, the Cranston bed, is  known here. It is
overlain and underlain by hard slaty shale. The bed appears to be in the
lower part of the Pennsylvanian rocks of the Narragansett Basin, although
outcrops are very scarce in the immediate vicinity. The pre-Carboniferous
crystalline rocks and basal Carboniferous conglomerate form a low irregular
escarpment a little over a mil~ to the west. Presumably, there is a general
dip to the east from this escarpment.
The Fenners Ledge mine is about the same distance east of the basal con-
tact of the Carboniferous rocks and about 2-3/4 miles northeast of the Cranston
mine. The discontinuous character of the meta-anthracite beds, as shown by the
drilling in Portsmouth, indicates that correlation of the Cranston bed with
that at the Fenners Ledge mine or with any other bed would be very uncertain.
Thickness, Structure, and Quality of Meta-anthracite Bed
The accompanying map (fig. 5) contains most of the known data about the
meta-anthracite bed. Most of the mine openings were carried to the top of the
meta-anthracite bed, as the coaly material would not stand as a satisfactory
roof.  It .is safe to assume, therefore, that the roof elevations of the map
are within a foot or two of the top of the bed. However, the floor elevations,
with a few exceptions indicated on the map, are above the base of the bed. At
a few localities it was possible to get elevations of the bottom and the top
of the bed and to describe the bed from bottom to top. These sections seem to
be representative, but individiiaily the different zones within the meta-anthra-
cite bed probably do not extend far.
Measured sections (positions shown on mine map, fig. 5) Section G (be-
tween 3d and 4th levels, 95 feet from end of 4th level)
Ft. In.
Top            Hard shale.
1        Soft meta-anthracite.
1       Bony meta-anthracite.
4        Medium hard meta-anthracite.
2        Bony meta-anthracite.
1        Meta -anthracite.
2        Bony meta-anthracite.
6   Meta-ahthracite.
6   Bony meta-anthracite.
1    6   Meta-anthracite, broken and mixed with bone.
6        Hard, bony meta-anthracite.
1    6   Soft shaly meta-anthracite.
4   Hard, bony meta-anthracite.
6   Soft meta-anthracite,
Bottom            Hard shale.

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